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Scientific approach to blast design. The influence of rock characteristics
78A
892218 Prediction of peak particle velocity and peak air pressure generated by buried explosion Gupta, R N; Pal Roy, P; Singh, B lnt J Min Geoi Engng V6. NI, March 1988, P15-26 Three sets of formulae, expressed as functions of dynamic elastic constants of rock, obtained from density, longitudinal and shear wave velocities, and some design parameters involved in a buried explosion, are explicitly derived to predict peak particle velocity (PPV) and peak air pressure (PAP). Separate equations are derived to estimate PPV and PAP for inside, outside and at the boundary of the crater zone. The formulae were applied to 7 rock types, including diorite, granite and limestone, and then verified using data from in situ controlled blasting.
892219 Scientific approach to blast design. The influence of rock characteristics Rorke, A J Quarry Manage Oct 1988. P33-42 Successful blast design produces a diggable rock pile with minimum adverse environmental impact. The outcome of the blast depends upon the nature and characteristics of the rock, the real performance of the explosive within the rock, and blast design. Rock characterisation in terms of dynamic and static properties, effects of dynamic properties on fragmentation and heave, influence of rock structure, and effects of explosives performance on blast qualities have been analysed using computer simulations.
892220 Model study of crater blasting Fourney, W L; Dick, R D; Simha, K R Y Rock Mech Rock Engng V21, N3, July-Sept 1988, P183-205 Cratering experiments to date have been unable to quantify the effects of stemming on cratering and fragmentation. To clarify this, small scale model tests using granite, Hydrostone (gypsum based), and plexiglass blocks were carried out. Results indicate that fracture and fragmentation in single hole crater blasting situations are not influenced by stemming. Radial cracks are formed before the crater formation process begins, and the crater initiates at the borehole wall and propagates to the surface. Crater formation is heavily dependent on stress wave effects and only in a minor way on borehole pressurisation. Scale effects and limitations on extrapolation of small scale model tests are discussed.
892221 Getting the right 'bang' in the right place at the right time Martin, D Tunn Tunnlg V20. N9, Sept 1988, P32-37 The non-electric detonator represented a significant development in blasting technology. It has no blast effect since it is confined in a tube, is not sensitive to electric currents and is safer than traditional detonators. Another improvement in blasting was development of emulite, a water-in-oil emulsion, which is safer than nitroglycerine, has good rock breaking qualities, and is stable and water resistant. The smooth blasting technique is outlined and charging equipment described.
892222 Some suitable patterns of drilling and controlled blasting in the surrounding of four hydroelectric projects in India Gupta, R N: Pal Roy, P: Bagchi, A; Singh, R B: Singh, B Proc Symposium on Rock Mechanics and Power Plants, Madrid, 12-16 Sept 1988 VI. P49-56. Publ Rotterdam: A A Balkema, 1988 Prevention of blasting damage to existing structures or part completed projects is essential. Although geological parameters are set, borehole, burden, spacing, stemming, explosive type, and delay firing may be varied to minimise vibration, often at little or no extra cost. A critical analysis of blast design is presented, and application of its results to four major projects described.
892223 Longer rounds to improve tunnelling and development work Niklasson, B; Holmberg, R; Olsson, K; Schorling, S Proc Tunnelling '88, London, 18-21 April 1988 P213-221. Publ London: IMM, 1988 Work in a Swedish iron ore mine where change to large scale sublevel caving is being investigated is presented. Development of the drilling, blasting, scaling, loading, and transport processes in drift driving is described. Currently available drill rigs are found to be inefficient in pulling drill rounds 7m long. Effects on setting times for other operations in the cycle, blast design, and performance are considered.
Crushing and grinding 892224 Fundamental study of dry and wet grinding from the viewpoint of breaking strength Kanda, Y; Abe, Y; Yamaguchi, M; Endo, C Powder Technol V56, NI. Sept 1988, P57-62 Differences between wet and dry grinding have been studied. Bending tests were conducted on a glass material to investigate the quantitative effects of water on bending strength, crack propagation and the relationship between strength and number of cracks. Results show crack length is greater in water than in air, bending strength is lower in water than in air, and a wet grinding process is useful from point of view of strength of solids.
Machine excavation 892225 Roadheader cutting heads and picks Hurt, K G Colliery Guard V236, N9, Sept 1988, P332-335 As roadheaders have become larger and more sophisticated, cutterhead design has assumed increasing importance. Design trends are illustrated, with the change from radial to point or forward attack picks, improvements in pick layout to minimise vibration, and water jet assistance being considered. Limits to roadheader cutting ability are also discussed.
892226 Criteria for selecting a boom-type roadheader Schneider, H Min Mag Sept 1988, P183-187 The simplest classification of boom type roadheaders is by weight. This allows the engineer to obtain information on approximate price on a weight basis, size, and field of applications. The areas where roadheaders in the 5 weight classes
~! 1989 Pergamon Press plc. Reproduction not permitted
892218 Prediction of peak particle velocity and peak air pressure generated by buried explosion Gupta, R N; Pal Roy, P; Singh, B lnt J Min Geoi Engng V6. NI, March 1988, P15-26 Three sets of formulae, expressed as functions of dynamic elastic constants of rock, obtained from density, longitudinal and shear wave velocities, and some design parameters involved in a buried explosion, are explicitly derived to predict peak particle velocity (PPV) and peak air pressure (PAP). Separate equations are derived to estimate PPV and PAP for inside, outside and at the boundary of the crater zone. The formulae were applied to 7 rock types, including diorite, granite and limestone, and then verified using data from in situ controlled blasting.
892219 Scientific approach to blast design. The influence of rock characteristics Rorke, A J Quarry Manage Oct 1988. P33-42 Successful blast design produces a diggable rock pile with minimum adverse environmental impact. The outcome of the blast depends upon the nature and characteristics of the rock, the real performance of the explosive within the rock, and blast design. Rock characterisation in terms of dynamic and static properties, effects of dynamic properties on fragmentation and heave, influence of rock structure, and effects of explosives performance on blast qualities have been analysed using computer simulations.
892220 Model study of crater blasting Fourney, W L; Dick, R D; Simha, K R Y Rock Mech Rock Engng V21, N3, July-Sept 1988, P183-205 Cratering experiments to date have been unable to quantify the effects of stemming on cratering and fragmentation. To clarify this, small scale model tests using granite, Hydrostone (gypsum based), and plexiglass blocks were carried out. Results indicate that fracture and fragmentation in single hole crater blasting situations are not influenced by stemming. Radial cracks are formed before the crater formation process begins, and the crater initiates at the borehole wall and propagates to the surface. Crater formation is heavily dependent on stress wave effects and only in a minor way on borehole pressurisation. Scale effects and limitations on extrapolation of small scale model tests are discussed.
892221 Getting the right 'bang' in the right place at the right time Martin, D Tunn Tunnlg V20. N9, Sept 1988, P32-37 The non-electric detonator represented a significant development in blasting technology. It has no blast effect since it is confined in a tube, is not sensitive to electric currents and is safer than traditional detonators. Another improvement in blasting was development of emulite, a water-in-oil emulsion, which is safer than nitroglycerine, has good rock breaking qualities, and is stable and water resistant. The smooth blasting technique is outlined and charging equipment described.
892222 Some suitable patterns of drilling and controlled blasting in the surrounding of four hydroelectric projects in India Gupta, R N: Pal Roy, P: Bagchi, A; Singh, R B: Singh, B Proc Symposium on Rock Mechanics and Power Plants, Madrid, 12-16 Sept 1988 VI. P49-56. Publ Rotterdam: A A Balkema, 1988 Prevention of blasting damage to existing structures or part completed projects is essential. Although geological parameters are set, borehole, burden, spacing, stemming, explosive type, and delay firing may be varied to minimise vibration, often at little or no extra cost. A critical analysis of blast design is presented, and application of its results to four major projects described.
892223 Longer rounds to improve tunnelling and development work Niklasson, B; Holmberg, R; Olsson, K; Schorling, S Proc Tunnelling '88, London, 18-21 April 1988 P213-221. Publ London: IMM, 1988 Work in a Swedish iron ore mine where change to large scale sublevel caving is being investigated is presented. Development of the drilling, blasting, scaling, loading, and transport processes in drift driving is described. Currently available drill rigs are found to be inefficient in pulling drill rounds 7m long. Effects on setting times for other operations in the cycle, blast design, and performance are considered.
Crushing and grinding 892224 Fundamental study of dry and wet grinding from the viewpoint of breaking strength Kanda, Y; Abe, Y; Yamaguchi, M; Endo, C Powder Technol V56, NI. Sept 1988, P57-62 Differences between wet and dry grinding have been studied. Bending tests were conducted on a glass material to investigate the quantitative effects of water on bending strength, crack propagation and the relationship between strength and number of cracks. Results show crack length is greater in water than in air, bending strength is lower in water than in air, and a wet grinding process is useful from point of view of strength of solids.
Machine excavation 892225 Roadheader cutting heads and picks Hurt, K G Colliery Guard V236, N9, Sept 1988, P332-335 As roadheaders have become larger and more sophisticated, cutterhead design has assumed increasing importance. Design trends are illustrated, with the change from radial to point or forward attack picks, improvements in pick layout to minimise vibration, and water jet assistance being considered. Limits to roadheader cutting ability are also discussed.
892226 Criteria for selecting a boom-type roadheader Schneider, H Min Mag Sept 1988, P183-187 The simplest classification of boom type roadheaders is by weight. This allows the engineer to obtain information on approximate price on a weight basis, size, and field of applications. The areas where roadheaders in the 5 weight classes
~! 1989 Pergamon Press plc. Reproduction not permitted